This proposal is to request support for a Keystone Symposia meeting entitled "HIV Vaccines", organized by Wayne C. Koff, Lynn Morris and Marcus Altfeld, which will be held in Banff, Alberta, Canada from March 21-26, 2010. Recent clinical trials, and in particular the STEP trial of Merck's adenovirus AIDS vaccine candidate, have produced results disappointing to the AIDS vaccine field generally, and have given rise to the sobering realization that the majority of vaccine candidates currently under development are unlikely to provide a truly effective AIDS vaccine. Hence there is now a broad consensus that the field needs to return to some fundamentals of immunology, and addressing how the human (and simian) immune system interacts with HIV and what will be required in an effective immune response against HIV to ward off establishment of infection. To stimulate new insights and approaches to these longstanding problems, Keystone Symposia is offering a novel conference format that facilitates a wider cross-fertilization of ideas among the wider HIV vaccine research community. To that end, the 2010 Keystone Symposia HIV Vaccines meeting will foster innovative ideas and new collaborations between immunology and vaccinology as it pertains to other viral diseases. Traditionally, Keystone Symposia has held concurrent meetings on HIV, integrating vaccines and pathogenesis discussions. For 2010, a new joint symposium of HIV Vaccines in conjunction with Viral Immunity will be convened. These concurrent symposia will greatly encourage cross-fertilization of ideas, allowing AIDS vaccine researchers to interact with viral immunologists who approach immunity from a more fundamental perspective.